I understand that, but my argument is that people usually spend up to the amount they are comfortable with because they are not rational actors.
I made this argument a lot when the prius was becoming popular. Lots of people said it was overpriced, that is cost 30k and there were similarly equipped cars for 20k. But that completely missed who was buying the car. If someone is in the market to spend 30k on a car, they most likely will, as they have entered into a different price bracket.
Same thing with apartments. Sure in Seattle you could share a space and pay less, my hunch (with no data to back this up) is that you probably wont. If I can comfortably afford 1-1.5k, then that's what I'm going to spend, regardless of city (Please don't nitpick and say 'Oh I share and pay less', I'm not speaking in absolutes).
You obviously will get a more space/features/quality in Seattle for the money, but my argument against this guides is they say you will actually be making x, because I'll be paying more in rent. but that's not the case. Yes you can argue the missed cost of having more space, but that's not what they compare. My bank account is going to be the same after rent regardless of the major city I'm in.
EDIT: Spelling and Grammar